Facsimile transmitter scanning system



May 2, 1950 w. G. H. FINCH ET AL 2,506,017

FACSIMILE TRANSMITTER SCANIQIING SYSTEM Filed Dec. 18, 1946 5 Sheets-Sheet 1 INVENTOR.

7 lam xJ -rj/ ATTORNEY.

y 1950 w. e. H. FINCH ET AL 2,506,017

FACSIMILE TRANSMITTER SCANNING SYSTEM Filed Dec. 18, 1946 3 Sheets-Sheet 2 4.2 LJLJ ATTORNEYS y 1950 w. G. H. FlNCH ET AL 2,506,017

FACSIMILE TRANSMITTER SCANNING SYSTEM Filed Dec. 18, 1946 5 Sheets-Sheet 3 T; F I 5. 4

INVENTOR5 ATTORNEYS Patented May 2, 1950 i 'FACSIMILE TRANSMITTER SCANNING SYSTEM William G. H. Finch, Newtown, Conn, and Gottfried H. Hohmann, Bronx, N. Y., assignors, by mesne assignments, to Pierce Company, Providence, R. I.

Application December 18, 1946, Serial No. 717,020

7 Claims. (01. 178.-13) 1 2 Our present invention relates to facsimile Another object of our invention is the protransmitters and more particularly to a scanning vision of novel means for halting and rapidly device of the type which is fed longitudinally returning the scanning apparatus to the beginwith respect to a radially rotating drum. ning of the scanning stroke after the scanning The type of scanning device which our present apparatus has completed any part of its scaninvention contemplates is that generally dehing operation. scribed in Patents Nos. 2,295,572 and 2,185,306. Another object of our invention is the provi- Essentially the transmitter comprises a rotating sion of a novel high pitch screw in conjunction drum around which a sheet carrying the image with a low pitch screw to provide for a fast to be transmitted is wrapped. As the drum 1'0- return of the scanning apparatus to the begintates radially, a photo-optic system is forced to ning of the scanning stroke. move longitudinally of the drum so that a com- A further object of our invention is the probination of the radial rotation of the drum and vision of a novel construction for a screw wherein longitudinal movement of the photo-optic system a high pitch screw may be obtained by winding results in a helical scanning line about the drum. if: a rectangular bead or wire around a shaft and Depending upon the speed of the drum and the soldering the head or wire thereto.

rate of movement of the photo-optic system with The foregoing and many other objects of our respect to the drum from sixty to two hundred invention will become apparent in the following scanning lines per inch may be obtained as a description and drawings in which:

helical trace about the drum. :3 Figure 1 is an elevation partly in cross section The photo-optic system ordinarily consists of of our novel scannin s a line source and means for focusing the light igure 2 is a sid V p y in ss Se on from the light source into a spot having a diamof our novel scanning system taken from line eter approximately equal to the width of one of 2--2 of Figure 1, looking in the direction of the the scanning lines or narrower than the same. arrows and showing the scanning device in the The photo-optic scanning system also includes position for ordinary slow speed scanning. another optical system for picking up th 176- gure 3 is a View correspond to at f fiected light spot and transmitting the same to Figure 2 showing, however, the feeding elements a photo-sensitive medium which translates the of. the scanning device arranged for the quick variations in the intensity of the light spot into return variations in intensity of electrical impulses Figure 4 is a view in perspective corresponding which may then be amplified and transmitted to that of Figure 3 showing the position of the by radio or wire to a receiver. elements of our novel scanning device for a quick It is common in the operation of such scanning return. systems to feed the complete photo-optic system 5 Figure 5 is a view in perspective corresponding longitudinal of the drum by a low pitch screw to the View of Figure 2, showing the arrangement which results in a relatively slow speed movement of our novel scanning device for scanning operaof the photo-optic system with respect to the tion with the elements approaching the position drum moving approximately at a speed of one for tripping the operating element into the quick inch per minute and thus taking approximately return position.

eight minutes for an eight inch wide drum. Referring now to the figures, the drum, not Also it has been common previously to provide shown, is located in front of the optical system some means for disconnecting the photo-optic is which performs the scanning operation in the scanning system from the screw so that the manner previously described, the said optical sysphoto-optic system may be quickly returned to tern iii being shown schematically. The optical h b inn f r mm nc n a n w sc n system is is provided with a lower support ll ope t n Without W t g for he slow opera o comprising a bar carried between the two side which would result from mere reversal of the frame members l2l2, the said bar being enscanning screw. gaged by the lower notch 53 of the housing for A specific and important object of our invento the scanning system ID.

6 0 1 is e D 'OV S O 0f simpl fie I l The scanning system H] may also be supported chanical means for rapidly returning the scanby other longitudinal horizontal bars engaging Hing apparatus to the e i i f the Scanning various portions thereof. The particular sup- Without i intervention of any manual ports for the scanning system comprise no part controls of a y i c5 of our invention but may be of the type gen- A further object o 9 nven n is the DlO- orally shown in the above mentioned Patents vision of automatic means for rapidly returning Nos. 2,295,572 and 2,185,806.

the scanning apparatus to the beginning of the The screw i5 is rotatably supported within the scanning stroke at the beginning of a scanning side frame members 52, i 2 and is driven in any operation. suitable manner from the appropriate power source, the power source being geared to synchronize with the rotation of the drum in order to obtain appropriate helical scanning.

The housing carries secured thereto in any suitable manner, as on the pivot 20, the lever 2|. The housing also carries secured thereto in any suitable manner as by the screw 22, the spring 23 which spring bears against the under side of the lever 2| in order to bias the left hand end of the lever upwardly with respect to Figure 2, or to bias the lever towards rotation in a counterclockwise direction.

The right hand end of the lever at its lower surface is provided with the half nut 25 which engages the screw I5 and this interengagement of the half. nut with the screw l5 provides for the scanning movement in a longitudinal direction at slow speed of the scanning system housing Ill. This interengagement is maintained as above pointed out by the spring 23 when the lever 2! is I of screw l5, the operative action of the high pitch thread 28 will be to return or move the scanning system back towards the beginning. The high pitch thread 28 also provides for an extremely rapid return.

Our novel device is arranged ordinaril so that the half nut 25 of lever 2| on the scanning housing it engages the slow speed scanning screw I5. When, however, the latch elements hereinafter described are tripped, the projection 27 of lever 2| engages the screw thread 28 on shaft 29 for a rapid return. The screw thread 28 on shaft 29 as seen in Figure 1, stops short of the left hand end of the machine so that after the rapid return is completed, the scanner idles in the starting position with the projection 21 up. It is necessary then to relatch the elements hereinafter described to cause the half nut 25 to engage the screw l5 in order to start the scanning operation once more.

The operating mechanism for the lever 2| comprises a bar 42 extending across the machine and pivotally secured at opposite ends on pin, 4!.

Pin 4| on the right hand side has also mounted thereon the lever 42 which is secured to the cross bar or plate by the lock 44 so that any rotation of lever 42 about pin 4| will result in corresponding swinging of the plate or bar 40 around the pins 4 A tension spring 46 is secured at 41 to the lower end of the plate All on the right hand side and is secured at 48 to a stationary part of the right hand side frame member l2 so that ordinaril the plate 42 is biased into counterclockwise rotation with respect to Figures 2 and 5. This rotation is resisted by the latch lever 52 which lever is pivotally mounted on the pin 52 carried by the side frame member i2 on the right side. Latch member 52 is biased into downward or counterclockwise rotation by the lever spring 53 supported on pin 54 also carried by the right hand side frame member 2.

Latch member has at its outer end the detent latching surface 55 which engages the pin 56 on the lower end of the lever 42 so as ordinarily to Iii) prevent the lever 42 and its plate 46 from moving in response to the bias of spring 52 from the position of Figures 2 and 5 to the positions of Figures 3 and 4.

The upper surface of the housing H) for the scanning system is provided with the cam 52, the said cam til being so arranged that it will move under and lift the latch member to at the completion of a scanning operation.

As shown in Figures 4 and 5, as the cam 6|) together with the scanning housing approaches the end of a scanning operation, the cam surface moves under the latch lever 52 and raises the latch lever 52 so that the detent surface 55 disengages the pin 56 on the lower end of the lever 42. This new permits the spring 52 to pull the plate at and the lever 42 from the position of Figures 2 and 5 to cause them to rotate in a clockwise direction to the positions of Figures 3 and 4.

The stationary pins in and fl carried by the right hand side frame member 2 limit the movement of the lever 42 and hence of the plate 42 between the positions of Figures 2 and 5 on one hand and Figures 3 and l on the other. When the lever 22 on the plate 42 is now pulled in a clockwise direction to the position in Figures 3 and 4, the lower edge 24 of plate 46 bears against the roller 15 on the lever 2i and causes the lever 2i to rotate in a counterclockwise direction around its pivot 22. The spring 46 is more powerful than the spring 23 so that this result may occur. This lifts the half nut 25 off of the scanning screw 55 and inserts the upper projection 21 into the thread 23 of the return screw 2 829 for a quick return.

The roller 15 combined with the length of the plate permits the lever 2| to be thus depressed during the entir return stroke 50 that the scarming device I3 will be carried all the way back. When the scanning device reaches the left hand position at the beginning of a scanning line it leaves the thread 23 on the shaft 23 and is thus in an idling position ready for the resump tion of the scanning operation. In order to start the scanning operation again, the lever 42 is rotated from the position of Figures 3 and 4 in a counterclockwise direction back to the position of Figures 2 and 5 against the tension of spring 26. This causes the pin 55 at the lower end of the lever 22 to be reengaged in th latching detent of the latch member 52 and thus holds the plate 22 in the position of Figures 2 and 5 so that the spring 23 may rotate the lever 2! to a position where the half nutZE engages the scanning screw 5.

At the completion of the scanning operation,

the cam 62 again trips the latch lever 58 to cause the plate is to rotate from the position of Figures 2 and 5 to the position of Figures 3 and 4 to effect a return of the scanning device.

Our device is also so arranged that the scanning device it: may be returned before the completion of a scanning stroke simply by manually moving the lever 22 from the position of Figures 2 and 5 to the positions of Figures 3 and 4. This can be done because the latching spring 53 and the latching surface 55 are so arranged that the exertion of a manual force on lever 42 which is somewhat greater than the force exerted by spring as will permit the latch lever 50 to be rgised out of engagement with the latching pin 5 By means of the foregoing, it will thus be seen that a simplified scanning system is provided wherein the scanning device may be fed longitudinally of the drum, at ordinary scanning speed and whereby the scanning device will be ordinarily returned to the initial position at the completion of the scanningoperation and without the intervention of any manual control. On the completion of the return, the scanning device will idle in the; Starting position until the lever 42 istripped to permitthescanning; device to reengage the scanning screw for a scanning operation.

Our novel scanning device is also so arranged that it may be tripped out of engagement with the feed screw at any point during the scanning operation and when tripped out of engagement with the feed screw, may be returned to the initial position.

In the foregoing, we have described; our invention solely in connection with an illustrative embodiment thereof. Since many variations and modifications of our invention will now be obvione to those skilled in the art, we prefer to be bound, not by the specific disclosures herein contained, but only by the appended claims.

We claim:

A scanning unit for facsimile apparatus, said facsimile apparatus comprising a rotatable drum, said scanning unit being mounted for Iongitudinal movement parallel to the axis of said drum while said drum rotates to scan a helical trace on said drum; a first rotatable screw for moving said scanning unit at scanning speed longitudinally of said drum in one direction; a second rotatable screw for moving said scanning unit at a relatively greater speed in the opposite direction back to the beginning of the scanning stroke; said first rotatable screw extending parallel to the drum and parallel to the path of movement of the scanning unit; means on said scanning unit engaging said first screw; said second rotatable screw extending parallel to the first screw, said second screw having a relatively greater pitch than said first screw; additional means on said scanning unit engageable with said second screw; a movable bar on said scanning unit; the aforesaid means on said scanning unit for engaging the first screw and the aforesaid means on said scanning unit for engaging the second screw being mounted on said bar, said bar being movable between two selected positions in each of which only one screw is enga ed.

2. A scanning unit for facsimile apparatus, said facsimile apparatus comprising a rotatable drum, scanning unit being mounted for longitudinal movement parallel to the axis of said drum while said drum rotates to scan a helical trace on said drum; a first rotatable screw for moving said scanning unit at scanning speed longitudinally of said drum in one direction; a second rotatable screw for moving said scanning unit at a relatively greater speed in the opposite direction back to the beginning of the scanning stroke; said first rotatable screw extending parallel to the drum and parallel to the path of movement of the scanning unit; means on said scanning unit engaging said first screw; said second rotatable screw extending parallel to the first screw, said second screw having a relatively greater pitch than said first screw; additional means on said scanning unit engageablewith said second screw; a movable bar on said scanning unit; the aforesaid means on said scanning unit for engaging the first screw and the aforesaid means on said scanning unit for engaging the second screw being mounted on said bar,

6 a d. e b n mo a le. betw en We. s ected positions in each of which only one screw is engaged; and means operable on the end of a scanning stroke automatically to move said bar; to disengage the first screw and engage the. second screw.

3. A scanning unit for facsimile apparatus, said facsimile apparatus comprising a rotatable drum, said scanning unit being mounted fcr longitudinal movement parallel to the axis of said drum while said drum rotates to scan a helical trace on said drum; a first rotatable screw for moving said scanning unit at scanning speed longitudinally of said drum in one direction; a second rotatable screwfor moving said scanning unit at a relatively greater speed in the opposite direction back to the beginning of the scanning stroke; said first rotatable screw extending parallel to the drum and parallel to the path of movement of the scanning unit; means on said scanning unit engaging said first screw; said second rotatable screw extending parallel to the first screw, said second screw having a relatively greater pitch than said first screw; additional means on said scanning unit engageable with said second screw; a movable bar on said scanning unit; the aforesaid means on said scanning unit for engaging the first screw and the aforementioned means on said scanning unit for engaging the second screw being mounted on said bar; said bar being movable between two selected positions in each of which only one screw is engaged; and manually operable means ior causing said bar to disengage one screw and engage the other screw.

4. A scanning unit for facsimile apparatus, said facsimile apparatus comprising a rotatable drum, said scanning unit being mounted for longitudinal movement parallel to the axis of said drum while said drum rotates to scan a helical trace on said drum; a first rotatable screw for moving said scanning unit at scanning speed longitudinally of said drum in one direction; a second rotatable screw for moving said scanning unit at a relatively greater speed in the opposite direction back to the beginning of the scanning stroke; said first rotatable screw extending parallel to the drum and parallel to the path of movement of the scanning unit; means on said scanning unit engaging said first screw; said second rotatable screw extending parallel to the first screw, said second screw having a relatively greater pitch than said first screw; additional means on said scanning unit engageable with said second screw; a movable bar on said scanning unit; the aforesaid means on said scanning unit for engaging the first screw and the aforesaid means on said scanning unit for engaging the second screw being mounted on said bar; said bar being movable between two selected positions in each of which only one screw is engaged; manually operable means for causing said bar to disengage one screw and engage the other screw; said manually operable means comprising a plate extending parallel to the path of movement of the scanning unit; said plate bearing against the bar carried by said scanning unit; a handle connected to said plate for moving said plate between two selected positions, movement of said plate to one of said selected positions causing said bar to engage one of said screws and movement of said plate to the other of said selected positions permitting said bar to engage th other of said screws.

5. A scanning unit for facsimile apparatus,

said facsimile apparatus comprising a rotatable drum, said scanning unit being mounted for longitudinal movement parallel to the axis of said drum while said drum rotates to scan a helical trace on said drum; a first rotatable screw for moving said scanning unit at scanning speed longitudinally of said drum in one direction; a

second rotatable screw for moving said scanning unit at a relatively greater speed in the opposite direction back to the beginning of the scanning stroke; said first rotatable screw extending parallel to the drum and parallel to the path of movement of the scanning unit; means on said scanning unit engaging said first screw; said second rotatable screw extending parallel to the first screw, said second screw having a relatively greater pitch than said first screw; additional means on said scanning unit engageable with said second screw; a movable bar on said scanning unit; the aforesaid means on said scanning unit for engaging the first screw and the afore- "'said means on said scanning unit for engaging the second screw being mounted on said bar; said bar being movable between two selected positions in each of which only one screw is engaged; manually operable means for causing said bar to disengage one screw and engage the other screw; said manually operable means comprising a plat extending parallel to the path of movement of the scanning unit; said plate bearing against the bar carried by said scanning unit; a handle connected to said plate for moving said plate between two selected positions, movement of said plate to one of said selected positions causing said bar to engage one of said screws and movement of said plate to the other of said Se1ected positions permitting said bar to engage the other of said screws; and spring means biasing said bar against the other of said screws.

6. A scanning unit for facsimile apparatus, said facsimile apparatus comprising a rotatable drum, said scanning unit being mounted for longitudinal movement parallel to the axis of said drum while said drum rotates to scan a helical trace on said drum; a first rotatable screw for moving said scanning unit at scanning speed longitudinally of said drum in one direction; a second rotatable screw for moving said scanning unit at a relatively greater speed in the opposite direction back to the beginning of the scanning stroke; said first rotatable screw extending parallel to the drum and parallel to the path of movement of the scanning unit; means on said scanning unit engaging said first screw; said second rotatable screw extending parallel to the first screw, said second screw having a relatively greater pitch than said first screw; additional means on said scanning unit engageable with said second screw, a movable bar on said scanunit; the aforesaid means on said scanning unit for engaging the first screw and the aforesaid means on said scanning unit for engaging the second screw being mounted on said bar;

ment of the scanning unit; said plate bearing against the bar carried by said scanning unit;

a handle connected to said plate for moving said plate between two selected positions, movement of said plate to one of said selected positions causing said bar to engage one of said screws and movement of said plate to th other of said selected positions permitting said bar to engage the other of saidscrews; spring means biasing said bar against the other of said screws; spring means biasing said plate in one of said selected positions; and latch means for holding said plate in the other of said selected positions against said spring biasing means.

7. A scanning unit for facsimile apparatus, said facsimile apparatus comprising a rotatable drum, said scanning unit being mounted for longitudinal movement parallel to the axis of said drum whil said drum rotates to scan a helical trace on said drum; a first rotatable screw for moving said scanning unit at scanning speed longitudinally of said drum in one direction; a second rotatable screw for moving said scanning unit at a relatively greater speed in the opposite direction back to the beginning of the scanning stroke; said first rotatable screw extending parallel to the drum and parallel to the path of movement of the scanning unit; means on said scanning unit engaging said first screw; said second rotatable screw extending parallel to the first screw, said second screw having a relatively greater pitch than said first screw; additional means on said scanning unit engageable with said second screw; a movable bar on said scanning unit; the aforesaid means on said scanning unit for engaging the first screw and the aforesaid means on said scanning unit for engaging the second screw being mounted on said bar; said bar being movable between two selected positions in each of which only one screw is engaged; manually operable means for causing said bar to disengage one screw and engage the other screw; said manually operable means comprising a plate extending parallel to the path of movement of th scanning unit; said plate bearing against the bar carried by said scanning unit; a handle connected to said plate for moving said plate between two selected positions, movement of said plate to one of said selected positions causing said bar to engage one of said screws and movement of said plate to the other of said selected positions permitting said bar to engage the other of said screws; spring means biasing said bar against the other of said screws; spring means biasing said plate in one of said selected positions; latch means for holding said plate in the other of said selected positions against said spring biasing means; a cam carried by said scanning unit, said cam engaging said latch and releasing said plate for movement under said spring bias at the end of a scanning stroke.

WILLIAM G. H. FINCH. GOTTFRIED H. HOHMANN.

:tEFERENCES BI'IED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,262,715 Wise Nov. 11, 1941 2,311,803 Wise -i Feb. 23, 1943 

